1. Field of the Invention
Aspects of the present invention relate to a digital transmission device, a digital reception device, and processing methods thereof, and more particularly, to a transmission system and a reception system capable of identifying a transmission mode or a reception mode using mode information, and a method for processing a stream using the same.
2. Description of the Related Art
Since the development of digital technology, there have been efforts of shifting from an analog broadcast system to a digital broadcast system. Accordingly, many countries have suggested diverse digital broadcast standards. Among them, the Advanced Television System Committee (ATSC) standard and the Digital Video Broadcasting-Terrestrial (DVB-T) standard are commonly used.
The ATSC standard adopts an 8-Vestigial Side Band (VSB) scheme, and the DVB-T standard adopts a Coded Orthogonal Frequency Division Multiplex (COFDM) scheme. Thus, the DVB-T standard is strong in a multi-path channel (in particular, in channel interference), and can easily implement a single frequency network (SFN). However, since the DVB-T standard has a low data transmission rate, it is difficult to implement a high definition broadcast therefore. In contrast, the ATSC standard can easily implement a high definition broadcast. Since each standard has advantages and disadvantages, each country is trying to compensate for the disadvantages and suggest an optimized standard.
As portable devices have become widely distributed, efforts to view a digital broadcast using a portable device are being made. Due to frequent mobility of a portable device, streams used for the portable device must be processed more robustly than normal streams. Therefore, a technology for efficiently transmitting additional streams using existing digital facilities is being developed.
In greater detail, a robustly processed stream additionally inserted into a normal stream that is transmitted to general broadcast reception devices is being developed, such that a portable device receives and process the additional stream. In this case, the additional stream can be inserted in any form and in any place. Therefore, if a reception system is not aware of characteristics on the form and/or place of the additional stream, the reception system can receive, but not process, the additional stream.